Thermostatic circuit closer



April 22 1924. P. ELSASSER THERMOSTATIC CIRCUIT CLOSER Filed Oct. 26 1921 Patented Apr. 22, 1 924. I g

UNITED I STATES.

PATENT OFFICE.

' PAULVELSKSISER, or nn'rnnxnnn, S WITZEBLAND 'rnnauos'ra'rrc cmcur'r cL'osER.

Application filed October 26, 1 921. 'SerialNo. 510,5a1.

To all whom it may concern:

Be it known 'that'I, PAUL ELsIissnR, a

' citizen of the Sn i'ss Confederation, residing According to the invention the fire alarm apparatus, which is inserted in an electric circuit which comprises further a source of current and an acoustic signal, comprises at least one contact drum revolubly arsur aces, and contact springs siding upon said drum. The contact drumis controlled by a spring and it has an arm held in position by a deviceof easily inflammablematerial. The arrangement is such that when fire breaks out the holding device is ignited and burned, whereby the arm of the contact drum is released and the drum is revolved into the contact position by the action of the spring. I

In order that the invention may be clearly understood, I shall proceed to describe the same with reference to-the form ofconstruction shown on the accompanying drawing, wherein Fig. 1 is a front elevation of the apparatus with the diagram of the electric consurfaces f upon its circumference which are 7 formed preferably by layers of fibrous material sunk into the surface of the drum. The axles d are controlled by helical springs g which are attached with the one end to' one of the end faces of the corresponding drum and with the other end to said supports 0, so that the drums e have'the tendency to adopt the position in which the.

contactis established. The front ends of the axles d are bent to form upwardly directed arms which are connected with one ranged upon a plate and havin insulating 1 another by a holding device 71 which is made for instance of celluloid. Instead of using a celluloid plate as holding device, a body of any other easily affected material could be used, for instance of a material which melts at;60. k are contact springs which bear against the drums e and which are fixed by means of screws Z upon insulating plates .m arranged upon the base plate a. n are contact screws with which the ends of the'leads are connected.

-A protecting case 0 covers the drums e and the blade springs is, said casing'having slots through which the arms h project. Another protecting casingp is placed over the arms h;-it is open at the front end and hasan aperture: p in the rear wall which permits the access of the flames to the holding body 2'. A wire spring g is, arranged upon the front wall of the casing 0 which has bent ends designed to limit the inward movement of the arms Jh. 1'1 is the battery and can electric alarm clockwhich is operated when the circuit is closed. Instead of the alarm clock any other convenient acoustic devlce can be used, e. g. a siren, a horn or the like. g

It is evident that one drum 6 would .be suflicient in which case the one arm h would be attached by the holding device 2' with a fixed support arranged at any convenient point.

When fire breaks out the holding body i is'destroyed and releases the arms h, so that the drums e can revolve under the action of the springs g and the insulating surfaces 7 are moved away from under the contact springs, whereby the circuit is closed.

The use of two drums as shown increases the security of operation as the circuit is closed even if one of the springs (1 should be defectuous as the connection of the two adjacent blade springs is sufficient to close the circuit.

1. A thermally controlled circuit closer comprisingin combination with a base plate, spring controlled contact elements pivotally mounted upon said base plate and consisting of revoluble drums, insulating surfaces upon said drums, contact springs sliding upon said drums, an arm projecting from the axle of each contact drum, and easily fusible means for holding said arms in their circuit interrupting position so that at the destruction of this holding means by the heatdeveloped from a fire the drums adopt automatically the circuit-closing position.

2. A thermally controlled circuit closer comprising in combination with a base plate, two parallel contact drums revolubly mounted upon said base plate, insulating surfaces upon said drums, contact springs sliding upon said. drums, an arm projecting from each of the axles of said drums and an easil fusible holding means connecting said arms of the two drums in the circuit-interrupting position.

A. thermall controlled circuit closer comprising in combination with a base plate, supports upon said base plate, two parallel drums revolubly mounted in said supports, insulating surfaces upon said drums, contact springs sliding upon said drums, an axle for each drum having an extension at one end, a head at the free end of said extension and an easily fusible holding means for connecting said heads of the two axles in the circuitinterrupting position.

4. A thermally controlled circuit closer comprising in combination with a base plate. spring controlled contact elements pivotally mounted upon said base plate and consisting of revoluble drums, insulating surfaces upon said drums consisting of pieces of fibrous material sunk into the circumferences of said drums, contact springs sliding upon said drums, an arm projecting from the axle of each contact drum, and easily fusible means for holding said arms in their circuit-interrupting position so that at the destruction of this holding means by the heat developed from a fire the drums adopt automatically the circuit-closing position.

5. A thermally controlled circuit closer comprising in combination with a base plate, spring controlled contact elements pivotally mounted upon said base plate and consisting of revoluble drums, insulating surfaces upon said drums, contact springs sliding upon said drums, an arm projecting from the axle of each contact drum, and easily fusible means for holding said arms in their circuit interrupting position so that at the destruction of this holding means by the heat developed from a fire the drums adopt automatically the circuit-closing position, a protecting ring partly covering the contact drums and elastic abutment elements on said casing designed to limit the movement of said arms in inward direction.

In testimony whereof I aflix my signature in presence of two witnesses.

PAUL ELSi-QSSER.

Witnesses C. M. MILLIER, G. L. FRANK. 

